The evolution of the public switched telephone network has resulted in a variety of voice applications and services that can be provided to individual subscribers and business subscribers. An open standards-based Internet protocol (IP) network, such as the World Wide Web, the Internet, or a corporate intranet, can provide an alternative typically referred to as “Voice Over IP” (VOIP) that may provide more complex telephony type services involving call control for multiple simultaneous call sessions such as conference bridging, or single number reach (SNR) applications where a calling party attempts to reach a remote telephone using the dialed number (DN) of another telephone (typically an office telephone communicating on a local area network (LAN) with other office telephones).
In particular, a single number reach application provides a calling party an option to either leave a message, or wait while the single number reach application attempts to contact the subscriber at different telephone numbers (e.g., work, cellphone, home, etc.); assuming the single number reach application is able to locate the subscriber, the single number reach application may play an announcement identifying the calling party, allowing the subscriber to either connect with the calling party or send the calling party to the subscriber's voice mailbox. Hence, deployment of a single number reach application requires an architecture that enables call control for multiple simultaneous call sessions.